EP1722987B1 - Body acting as a support for a tyre in the event of deflation and tyre set provided with said body - Google Patents

Abstract

The tubeless tyre (10), having beads (11) sealed with a wheel rim (12), incorporates a toroid inner chamber (30) with a skin (31) of a deformable elastomer material over a supporting frame (311). In the event of the tyre sidewall (12) being punctured the skin is able to expand quasi-instantaneously to block the hole at least temporarily and limit any loss of pressure in the tyre.

Description

The invention relates to tires and in particular the devices limiting the pressure loss resulting from a perforation of said tires.

In use on a vehicle equipped with tires mounted on the rim and inflated to their inflation pressure, it is found that a perforation of a sidewall of a tire causes a very rapid loss of the internal inflation pressure, said perforation being able to result in example of aggression by an object outside the tire or a breakage of the tire structure itself.

Pneumatic / rim assemblies have been developed (see in particular patents US 6092575 , US6418992 , US 5634993 , US 5785781 ) which, in such a situation, provide an operation comparable to that of the inflated tire, thus allowing the user to continue driving for at least a minimum distance; in addition, deflation warning devices are provided in the vehicle equipped with such assemblies to prevent the user from loss of pressure.

Another alternative is to modify the structure of the tires to allow them, even in the deflated state, to withstand a load substantially equivalent to their nominal load without significant change in performance at least for a minimum distance of use.

However, not all vehicles, and in particular heavy goods vehicles, are today equipped with such assemblies or tires. An object of the present invention is to reduce the effects of perforation for tires of the usual type.

In order to ensure that the effects of a perforation on tires of the usual type are as instantaneous as possible, it has been proposed in the state of the art solutions consisting, for example, of placing inside each type tire. another tire of suitable dimensions so that, during a perforation of the tire or a pressure loss of the latter, the internal tire serves to support the external tire. Nevertheless, the difference in behavior between the state of the inflated initial tire and the state of the tire supported by an internal tire is very different. important (it is no longer the external tire that works but the internal tire) and may cause difficulties in adaptation by the driver of the vehicle in this situation.

Also known devices placed in the tire which, while not inflated in normal use, can reduce the pressure loss in the tire during a perforation of the latter. The document published under reference US2002 / 0121325 describes such a device. This device comprises a toroidal tube of reduced dimensions relative to the volume of the tire cavity, in order to avoid as much as possible the interactions between the tire and the tube in normal (ie inflated pneumatic) operation. tube being provided with at least one opening for communicating the cavity defined by the tube with the cavity of the tire in which the tube is placed. During a perforation of the tire, the inflation pressure in the cavity delimited by the tire and the toroidal tube escapes while said tube having only a small opening maintains a pressure that is almost unchanged for at least a sufficient time at the driver to join a repair station. The action of the pressure in the tube, of dimensions appropriate to those of the tire inside which it is arranged, comes to press it against the beads of the tire, which has the effect of holding the beads against the rims of the rim and to limit the pressure loss in the tube.

However, if it is easy to have a plating of the tube against the beads in the case of a tire aspect ratio (section height / section width) at least equal to 0.80, this is no longer the case with a so-called "low-ratio" tire, that is to say less than 0.80, since the swelling tube necessarily adopts a purely pneumatic equilibrium shape which tends to move said tube away from the tube. pneumatic.

Finally, this tube does not make it possible to prevent a change in the behavior of the tire since there is a more or less long delay between the beginning of the loss of pressure of the cavity formed between the tire and the tube and the moment when the tube is itself solicited as support. Finally, when the tire is supported by the inflated inner tube, the geometry of the tire is substantially modified compared to that which the same tire adopts when it is inflated and not perforated.
The document WO 01/53120 A2 shows a medium support tire assembly corresponding to the preamble of claims 1 and 20.

The object of the invention is to propose a device placed inside a tire which allows both a reduction of the inflation pressure loss of the tire having a perforation while maintaining the tire in its initial form. inflated. Another objective is to limit in time the transitional phase of passage of a state of the inflated tire in which no device interacts with the tire to a state in which a device according to the invention comes into action.

According to the invention, there is provided an assembly formed of a rim and a tubeless tire (called "tubeless" in English) having two beads intended to cooperate with the mounting rim comprising edges or hooks to limit the axial distance between the beads of the tire, a vertex and flanks connecting the beads at the top, the tire defining a cavity with the mounting rim. Inside this cavity is placed a toric-shaped body delimiting, when the tire is inflated, a cavity internal to said body and an external cavity with the tire, the inner and outer cavities being communicating with one another so that the body is subjected to any inflation effort in normal use (that is to say inflated pneumatic to its pressure of use).

This body comprises a skin that can easily deform under the effect of an inflation pressure, this skin being made of elastomeric material and reinforced by a carcass reinforcement anchored to two inextensible reinforcement circumferential reinforcement whose inner diameter is smaller than the diameter. maximum of the rim (corresponding to the diameter of the points of the radially outermost rim hooks), this carcass reinforcement being able to withstand the forces of an inflation pressure corresponding to the nominal inflation pressure of the pneumatic tire. inside which the body is placed, this body being characterized in that, during a perforation of the tire, the skin of said body has an appropriate flexibility to deform, at least locally and almost instantaneously, to obstruct the less temporarily said perforation and thus limit, at least temporarily, the loss of inflation pressure in the cavity e xerne between the tire and the body, and thus ensure a transition "soft" to an equilibrium state in which the body is deformed and serves as a support for the tire after complete loss of pressure in the external cavity.

For soft skin, it is necessary to understand a skin having very low or even almost zero structural stiffness with the exception of the rigidity of extension of its armature. Such skin having the shape of a torus loses its torus shape when it is placed on a flat surface without support element.

To achieve the desired result, it is preferable that the reinforcement of the body is from the initial state (state in which the tire is inflated with the body placed at the interior) close to the beads of the tire so as to have, by axial separation under the action of the pressure in the internal cavity of the body, a contact action on the beads and maintaining them in contact with the flanges of the mounting rim. In this contact between parts of the body and the inside of the tire, it is expected that the area of the areas in contact between the body and the tire increases relative to the contact surface that exists when the tire is in the initial state.

Preferably, these additional contact surfaces may be provided to ensure a sufficient seal between the tire and the body in order to maintain the pressure in this body as long as possible while the contact surfaces with the tire in the initial state comprise means to allow the inflation atmosphere to pass between the body and the tire. Preferably, the body has only very small contact surfaces with the tire in normal use (ie non-perforated inflated pneumatic tire) so as to avoid interactions between the tire and the body (friction contact between them). ).

In order to have the desired effect, the body must adopt locally and almost instantaneously, under the action of a low internal pressure (that is to say less than or equal to 0.1 bar), a form close the perforated tire. For this purpose, the volume of the body's internal cavity in the inflated tire must be suitable for the action of a low pressure to be effective. In particular, it can be provided that the body comprises in its cavity a frame independent of said body and such that this frame imposes a geometry to the body such that the volume of the internal cavity is at least equal to one third of the volume of the maximum tire cavity.

By frame independent of said body, it must be understood that either this frame is not connected to said body or it is but to a degree that does not prevent the change of shape of the body inside a subject tire abruptly to a perforation.

In a variant, the body has the shape of an open torus, in the manner of a tire, the opening being made substantially between the inextensible reinforcement of circumferential reinforcement of said body.

In another variant, the body is of closed-ring shape and comprises at least one orifice for communicating the internal and external cavities when this body is in place in a tire and at the same time having an effect of confining the inflation pressure. in the internal cavity of the body during the perforation of the tire.

In another variant, the frame of the body is formed by at least one O-ring spring wound around the rim, the shape taken by this spring imposing a geometry appropriate to said body in order to define with the rim a suitable internal cavity volume to have the desired effect. This spring may be spiral type or formed of a succession of rings that can be deformed elastically (that is to say, returning to its original shape after deformation).

In a variant, the carcass reinforcement of the body comprises at least two plies (or stacks) each formed of a plurality of reinforcing elements, in the form of threads or textile cords, making, in the radially most outside the body, angles at least equal to 25 ° with the circumferential direction, the reinforcing elements of the plies being crossed with each other. These reinforcing elements of the carcass reinforcement of the body may be aromatic polyamide wires or cables.

Moreover and to ensure better mechanical strength of the body when the latter serves as a support for the tire, the body may comprise in its summit part, that is to say its radially outward portion, a reinforcing reinforcement formed a plurality of reinforcements in the form of son, continuous or discontinuous cables. Advantageously, the reinforcements of the summit part are arranged in a direction making an angle at most equal to 10 ° with the circumferential direction.

The object of the invention is also a body having the shape of a torus of revolution about an axis of rotation and intended to be placed inside a tire to seal a possible perforation of said tire and reduce the speed of loss of pressure in the tire while providing a support inflated to said tire. This body comprises a skin made of elastic elastomer material that can be deformed, reinforced by a carcass reinforcement anchored to two inextensible reinforcing circumferential reinforcement elements integrated into said skin, these inextensible reinforcements having an inner diameter smaller than the maximum diameter of the rim, this reinforcement carcass being able to withstand the forces of an inflation pressure corresponding to the nominal inflation pressure of the tire within which the body is placed.

This body is characterized in that, under the effect of a low local pressure, that is to say close to 0.1 bar, at least locally said body comes almost instantly in contact with the perforated sidewall of the tire and in that that said body is able to withstand an inflation pressure equal to the pressure of the tire in which it is intended to be placed.

At least locally, it is understood that, seen in a plane containing the axis of rotation and passing through the perforation of the tire, the profile of the body is at least in contact with the tire at the location of the perforation.

To achieve such an almost instantaneous effect, it is necessary to adapt the flexibility of the skin to allow it to deform at least locally until it closes the perforation.

The body according to the invention may have the shape of an open or closed torus. In the latter case, it is provided with at least one reduced-size opening, this opening being located radially inside the circumferential reinforcing inextensible reinforcements serving as anchoring to the carcass reinforcement.

Each inextensible reinforcement for circumferential reinforcement of the body according to the invention may be an aromatic polyamide rod, said rod making it possible to withstand the forces of an inflation pressure equal to the inflation pressure of the tire inside which said body is placed. while facilitating the setting up.

Other features and advantages of the invention emerge from the description given hereinafter with reference to the accompanying drawings which show, by way of non-limiting examples, embodiments of the subject of the invention.

The figure 1 shows an assembly according to the invention comprising a tire mounted on its mounting rim and inflated to its operating pressure within which a body has been placed;

The figure 2 partially shows the same set as that shown in figure 1 wherein, following perforation of the tire, the body has deformed locally to seal the perforation and reduce the deflation speed of the tire;

The figure 3 shows the same set a few moments after all the pressure in the tire has been canceled (the external cavity is then at atmospheric pressure);

The figure 4 shows a frame variant of a body according to the invention used in all Figures 1 to 3 ;

The figure 5 shows a variant according to the invention according to which the frame of the body comprises a ring-shaped annular spring;

The figure 6 shows a variant of framework to have a non-inflated body having a shape is not symmetrical.

The figure 1 shows an inflated pneumatic assembly 1 formed by a tire 10 of dimension 495 / 45R22.5 (drop center tire) mounted on a mounting rim 20 having inclined seats 21 at an angle equal to 15 °. The tire 10 comprises beads 11 in contact with the seats 21 of the rim 20, flanks 12 connected to a top 13 whose radially outer portion is intended to come into contact with the roadway during travel.

Inside the tire 10 is mounted a body 30 of toric geometry which when the tire is inflated, delimits firstly an external cavity Ve located between the tire and said body and, secondly, an internal cavity Vi located inside said body.

The body 30 is formed of a skin 31 shaped torus open and ending at each of its ends not a bead 32. This skin 31 is made of rubber reinforced by a carcass reinforcement 311 anchored in each bead 32 by turning around a circumferential reinforcement reinforcement 33 of bead.

The carcass reinforcement 311 is formed, in this case, two plies each armed with a plurality of polyamide reinforcements and crossed from one sheet to another. Before shaping, the skin 31 is, for example, made on a cylindrical shape, not shown, whose diameter corresponds substantially to that of circumferential bead reinforcing reinforcements. The plies of the carcass reinforcement are placed on this cylindrical shape with an angle of the reinforcements of said plies chosen according to the desired final angle. Tests were made with placement angles equal to 55 °, 58 ° and 82 ° (angle measured with respect to the circumferential direction).

After laying on this form, the skin is shaped to take a shape as shown in FIG. figure 1 ; the angles of the reinforcements of the plies of the carcass reinforcement are of course modified during this phase of the manufacture of the skin (the angles obtained are respectively 27 °, 37 ° and 78 °).

The beads 32 of the body 30 are reinforced by reinforcements 33 comprising a set of polyamide reinforcements whose resistance is suitable to withstand at least the forces exerted by the carcass reinforcement 311 of the skin when the latter is inflated to a pressure equal to the tire pressure intended to be equipped by said body.

Furthermore, the body 30 comprises, disposed within the skin 31, a frame 40 imposing its geometry to said skin 31 when the latter is not inflated. This frame 40 (shown with the figure 4 ) comprises a flexible circumferential band 41 and circumferentially inextensible on which are fixed several rigid arches 42 so that said band 41 is substantially at the same distance from the axial ends of the arches 42. The circumferential band 41 is in this case a metal strip of width equal to 55 mm and thickness 0.8 mm and length equal to 2.5 m. This inextensible band 41 is flexible enough to be flexed to reduce its size and thus allow its introduction to the interior of the skin before it resumes its original shape. In the case shown in figure 4 there are eight hoops 42 fixed integrally to the circumferential band and uniformly distributed in the circumferential direction on the band 41; each arch 42 is molded in a suitable geometry and is formed of a resin reinforced by aromatic polyamide reinforcements (it is also possible to use reinforcements of fiberglass or carbon).

By appropriate geometry of a hoop means a transverse geometry (that is to say in the direction of the axis of rotation of the tire / rim assembly) which is appropriate for imposing a mean meridian section geometry to the skin so as to delimit the internal and external cavities. In particular, each arch 42 comprises an inverted portion 421 at each of its axial end to prevent damage to the skin 31 with said ends.

The overall length of the arches 42 is equal to 396 mm.

In the configuration shown with the figure 1 the tire 10 is inflated by means of a single valve (not shown); means (for example, striations on the body beads) are provided so that the same inflation pressure is established both in the internal cavity Vi and in the external cavity Ve.

In the present case, the circumferential length of the web 41 of the framework 40 is chosen so that the body does not come into contact with the tire when the latter is inflated and carries its nominal load, with the exception of the beads 32 of the body 30 which are in contact with the beads 11 of the tire 10.

Preferably, the circumferential length of the band 41 is determined so that the volume of the internal cavity Vi is at least equal to half the volume of the external cavity Ve. Even more preferably, the volume of the internal cavity Vi is at least equal to the volume of the external cavity Ve.

In this configuration, it is essential that the body 40 is not subjected to the inflation pressure so that it can act effectively as will be described now with the support of the figure 2 .

The figure 2 shows a partial section of the tire 10 side of the sidewall 12 having a perforation 100 following an external aggression to the tire. Almost instantaneously, the inflation fluid present the external cavity Ve begins to escape through the perforation 100 and the pressure in the external cavity Ve tends to decrease locally (at least initially). This local variation of inflation pressure in the external cavity Ve creates an imbalance of the pressures between the external cavity Ve and the internal cavity Vi. It follows that the skin 31 is then instantly and locally subjected to this pressure difference; in view of its great flexibility, it deforms locally until it obturates the perforation 100.

With this first mechanism, it is possible to reduce the leakage rate of the inflation fluid in the external cavity Ve.

In the instants which follow this intermediate state, and although the leakage rate of the inflation fluid is reduced, the pressure drop in the external cavity Ve will, however, affect the whole of said cavity. During this pressure drop, there is a progressive inflation of all the skin 31 which finally adopts a geometry as represented in FIG. figure 3 , the beads 32 of the body coming against the beads of the tire.

The pressure difference between external cavity Ve and internal cavity Vi also leads to further plating the beads 32 of the body 30 against the beads 11 of the tire 10, which ensures a maintenance of the beads 11 of the tire on the rim. The means which had allowed the inflation of the tire can be advantageously provided to close during this contacting under high pressure so as to limit the leakage pressure leakage between the body 30 and the tire. It should be noted that even if a leak exists, it remains low and the body 30 according to the invention makes it possible to avoid a sudden and instantaneous loss of tire performance.

The figure 3 shows the perforated tire 10 after the external cavity Ve has reached a pressure value equal to the atmospheric pressure. In this state, the skin 31 (not secured to the frame 40) has deformed so as to occupy a large part of the inside of the tire 10. The pressure in the internal cavity Vi is still sufficient to maintain the tire in a configuration rather close to that which was hers before perforation. This state is sufficient to avoid sudden deflation and instantaneous loss of tire running performance. On this figure 3 it can be seen that the arches 42 can be flexed by the skin 31, which justifies the presence of the turned parts 421 in order to prevent the ends of said arches from damaging the skin.

As shown again figures 2 and 3 the structure of the skin is suitably reinforced so as to be able to withstand the forces imposed both in the intermediate phase of filling the perforation (very short phase following the perforation) and in the final phase of inflating the skin inside the tire.

As an alternative embodiment of the plies of the carcass reinforcement, it is possible to use, in place of polyamide reinforcements, textile reinforcements or even small diameter metal wires (that is to say of diameter at most equal at 0.2 mm). It is also possible to use staple fibers of diameter at most equal to 0.2 mm.

To ensure a good fit of the body inside the non-perforated inflated tire when the tire and the body are subjected to centrifugal forces, it is advantageous to reinforce the radially outermost part of the skin with a reinforcement. vertex comprising a plurality of reinforcements of appropriate rigidity. For example, this frame may be formed of circumferentially oriented textile threads or threads (i.e. at an angle of 10 ° or less with the circumferential direction). Discontinuous reinforcements may also be used for either the crown reinforcement or the carcass reinforcement. Corrugated reinforcements may also be used to reinforce the crown reinforcement.

The figure 5 shows a frame variant 400 of a body 30 according to the invention, this frame being formed of an annular spring 401 with an O-base placed inside the skin 31 of the body so as to give the body a geometry such that that body 30 delimits with the rim 20 an internal cavity volume and with the tire 10 an external cavity volume, said cavities being communicating with each other. The spring 401 used in this variant has the advantage of being put in place in the skin 31 by acting on its elasticity of deformation and thus to facilitate the mounting of the body in the tire. This same elasticity of deformation allows the spring to resume its initial geometry and thus to impose the desired geometry body once in place in the tire. In addition, in this variant, the body comprises a top portion 34 reinforced by a reinforcing reinforcement 341 formed of a plurality of reinforcements in the form of continuous or discontinuous son or cables. Preferably, the average angle of said reinforcement reinforcement reinforcements of the top portion 34 with the circumferential direction is at most equal to 10 °.

The figure 6 shows, schematically, a variant of framework allowing to have a body in use not inflated whose geometry in a meridian plane is not symmetrical by relative to a median plane (plane perpendicular to the axis of rotation and passing equidistant from the beads of the body when the latter is in place in the tire). For the sake of simplification, the same references are used here to designate elements comparable to those of the variant shown with the Figures 1 to 4 .

The frame 40 is here formed of a plurality of flexible arches 42 arranged transversely and fixed at their axial ends to two rods 41 ', 41 "circumferentially inextensible, said rods 41', 41" having different circumferential lengths one of the other. The introduction of this framework 40 into a skin 31 of a body 30 of appropriate profile leads to obtaining a meridian profile unsymmetrical with respect to a plane perpendicular to the axis of rotation. Thus, it is possible to bring the profile of the skin 31 of at least one sidewall of the tire.

Flexible arch means here a hoop can bend under a low force so as to allow axial approximation of the inextensible rods circumferentially after the tire, inside which is placed the body has been perforated.

In this way, it may be possible to further increase the efficiency of the body according to the invention by reducing the shutter time on the nearest sidewall; this arrangement may be useful when it is known that it is the sidewall facing outward of a vehicle that is most subject to aggression and therefore perforations.

The object of the invention can be used in the case of tires of the usual type whether for passenger vehicles, trucks, off the road or for aircraft. Of course, the tires designed to operate even in the event of total or partial deflation (in particular tires incorporating under-inflated rolling means or the assembled assemblies recalled in the introduction) may be additionally provided with a body according to the invention in the purpose of reducing the speed of loss of inflation pressure in case of perforation.

Claims (20)

1. An assembly (1) formed of a tubeless tyre (10) mounted on a mounting rim (20), this tyre having two beads (11) designed to cooperate with the mounting rim (20) comprising edges for limiting the axial distance between the beads of the tyre, this tyre having furthermore a crown (13) and sidewalls (12) connecting the beads (11) to the crown, this tyre defining with the mounting rim (20) a cavity inside which there is placed a body (30) toric in form and defining, when the tyre is inflated, a cavity inside said body (30) and an outer cavity with the tyre, the inner and outer cavities intercommunicating in such a way that the body (30) is not subject to any inflation force in normal use (i.e. tyre inflated to its utilisation pressure), this body (30) comprising a skin (31), of resilient elastomeric material capable of deformation, reinforced by a carcass reinforcement (311) anchored to two inextensible circumferential reinforcement structures (33), whose internal diameter is less than the maximum diameter of the rim (20), this carcass reinforcement (311) being capable of withstanding the forces applied by an inflation pressure corresponding to the rated inflation pressure of the tyre inside which the body (30) is placed, this body (30) being characterised in that, in the presence of a puncture (100) in the tyre, the skin (31) deforms, at least locally and virtually instantaneously, in order to block at least temporarily the puncture (100) so as to limit, at least temporarily, the loss of inflation pressure in the outer cavity between the tyre and the body, and to ensure transition to a state of equilibrium in which the body (30) is deformed and serves as a support for the tyre (10) after complete loss of pressure in the outer cavity.
2. An assembly (1) according to claim 1, characterised in that the body (30) is a closed torus provided with at least one opening for communication between the inner and outer cavities.
3. An assembly (1) according to claim 1, characterised in that the body (30) is a torus which is open substantially axially between the inextensible circumferential reinforcement structures (33) of said body.
4. An assembly (1) according to any one of claims 1 to 3, characterised in that the carcass reinforcement (311) of the body (30) comprises at least two plies each formed of a plurality of reinforcement elements, in the form of textile cords or cables, forming, in the radially outermost part of the body, angles of at least 25° with the circumferential direction, the reinforcement elements of the plies being crossed over one another.
5. An assembly (1) according to claim 4, characterised in that the reinforcements of the carcass reinforcement (311) of the body (30) are cords or cables of aromatic polyamide.
6. An assembly (1) according to any one of claims 1 to 5, characterised in that the body (30) comprises a crown part (34) radially towards the outside, said crown part comprising a reinforcement structure (341) formed of a plurality of reinforcements in the form of continuous or discontinuous cords or cables.
7. An assembly (1) according to claim 6, characterised in that the reinforcement structure of the crown part (34) of the body (30) comprises a plurality of reinforcements disposed in a direction forming an angle of at most 10° with the circumferential direction.
8. An assembly (1) according to any one of claims 1 to 7, characterised in that the body (30) comprises a framework (40, 400) placed inside said body and independent of said body, said framework having the function of causing the body (30) to adopt a form defining an inner cavity volume at least equal to one third of the maximum cavity volume defined by the tyre (10) and its mounting rim (20).
9. An assembly (1) according to claim 8, characterised in that the framework (40) comprises at least one circumferential band (41) of a rigidity appropriate for imparting to the body (30) a circumferential length appropriate to said body and, firmly connected to said band (41), a plurality of bows (42) imparting their shape to the body (30) in the transverse direction.
10. A body (30) of toric geometry around an axis of rotation and designed to be placed inside an assembly formed of a tyre (10) mounted on a mounting rim (20) so as to seal any puncture (100) which said tyre (10) may suffer and to reduce the rate at which pressure is lost in the tyre while providing said tyre with an inflated support, this body (30) comprising a skin (31), of resilient elastomeric material, reinforced by a carcass reinforcement (311) anchored to two inextensible circumferential reinforcement structures (33) incorporated in said skin (31), these inextensible structures (33) having an internal diameter of less than the maximum diameter of the rim (20), this carcass reinforcement (311) being capable of withstanding the forces applied by an inflation pressure corresponding to the rated inflation pressure of the tyre inside which the body (30) is placed, this body being such that under the action of local pressure less or equal to 0.1 bar, said body (30) comes virtually instantaneously into contact with the tyre (10) at the site of the puncture (100), said body (30) is capable of withstanding an inflation pressure equal to that of the tyre (10) in which it is intended to be placed, this body being characterised in that the body (30) is a closed torus whose skin (31) is provided with at least one small opening, said opening being located radially to the inside of the inextensible circumferential reinforcement structures (33) providing anchorage for the carcass reinforcement (311).
11. A body (30) of toric geometry according to claim 10, characterised in that the body (30) is a torus open axially between the inextensible circumferential reinforcement structures (33) providing anchorage for the carcass reinforcement (311).
12. A body (30) of toric geometry according to any one of claims 10 to 11, characterised in that the carcass reinforcement (311) of the body (30) comprises at least two plies each formed of a plurality of reinforcement elements, in the form of textile cords or cables, oriented on the inflated body in directions forming angles of at least 25° with the circumferential direction, the reinforcement elements of the stacks being crossed over one another.
13. A body (30) of toric geometry according to claim 12, characterised in that the reinforcements of the carcass reinforcement (311) of the body are cords or cables of aromatic polyamide.
14. A body (30) of toric geometry according to any one of claims 10 to 13, characterised in that the body (30) comprises a crown part (34) radially towards the outside, said crown part comprising a reinforcement structure (341) formed of a plurality of reinforcements in the form of continuous or discontinuous cords or cables.
15. A body (30) of toric geometry according to claim 14, characterised in that the reinforcement structure of the crown part (34) of the body (30) comprises a plurality of reinforcements disposed in a direction forming an angle of at most 10° with the circumferential direction.
16. A body (30) of toric geometry according to any one of claims 10 to 15, characterised in that each inextensible circumferential reinforcement structure (33) is a bead wire of aromatic polyamide, said bead wire making it possible to withstand the forces applied by an inflation pressure equal to the inflation pressure of the tyre inside which said body is placed, while facilitating positioning.
17. A body (30) of toric geometry according to any one of claims 10 to 16, characterised in that the means of imparting a geometric shape to said body (30) consist of a framework (40, 400), of appropriate rigidity, placed inside the skin (31) while being independent of said skin (31), this geometric shape defining a cavity volume at least equal to one third of the internal volume of the tyre (10) in which the body(30) is intended to be placed.
18. A body (30) of toric geometry according to claim 17, characterised in that the framework (40, 400) comprises at least one circumferential structure (41, 41', 41 ") of suitable rigidity for imparting to the skin (31) a given circumferential dimension and, firmly connected to said circumferential structure (41, 41', 41 "), a plurality of transverse bows (42) imparting their shape to the body (30) in the transverse direction.
19. A body (30) of toric geometry according to claim 17, characterised in that the framework (40) comprises two circumferential structures (41', 41 ") of suitable rigidity for imparting to the skin (31) a given circumferential dimension at two axially distinct points, these two circumferential structures (41', 41 ") being connected by at least one bow (42) whose function is to hold said two structures axially apart.
20. A body (30) of toric geometry according to claim 17, characterised in that the framework (400) consists of at least one toric base annular spring (401) imparting its toric shape to the skin (31).

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